I've been digging around, the SOC definitely supports simultaneous video out like the vibrant does.
I'm trying to pin point whether or not the Nexus S uses the same headphone hardware as the rest of the Galaxy line. I can't seem to find anything about it. That's going to be the crucial point on whether it can be hacked in or not. My gut tells me samsung used the same parts as it would be most cost efficient way to do so.
The SOC actually supports 1080p over USB => hdmi connection, (the actual USB hardware is probably not in place though, as the only galaxy line that used HDMI is the EPIC and that has a seperate mini HDMI port).
We just need to find an interested dev to jump into the kernels and libraries. Can we say Bounty? I'm down for at least $15, if someone wants to organize the bounty.
This is complete BS is the Nexus S doesn't do TV out! I mean, I had to get over my little crying fit since It doesn't have an external SD slot (like my Vibrant), but NOW since it doesn't do TV out, why should I get the f*@! phone . Is it worth turning in my sweet 'rooted' Vibrant running an awesome NERO v5 rom for the 'Pure Google Experience' I was willing to throw it all away to get my Nexus S, so I can have untethered updates straight from Google, BUT NO TV OUT!!!???!!! I use VR Glasses on my Vibrant to watch movies, surf, and play games, but since Nexus S doesn't support TV out, then F#@* IT!!!
I guess i'll wait if there is a software solution for TV out.